Pump device for casting processes

ABSTRACT

A pump device includes a drive unit, a pump unit and a transport unit. The drive unit includes a base frame, and a variable-speed drive device disposed on the base frame. The pump unit includes a rotating shaft driven by the drive device, a fan blade co-rotatably mounted to the rotating shaft, a drain housing receiving the fan blade, and a suction housing in fluid communication with the drain housing. The transport unit includes a plurality of transport tubes in fluid communication with the drain housing.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Patent Application No.106120518, filed on Jun. 20, 2017.

FIELD

The disclosure relates to a pump device, and more particularly to avariable-speed pump device for casting processes.

BACKGROUND

A conventional pump device is used in a casting process for transportinga melted material from a crucible to a mold cavity. The conventionalpump device includes a driving motor and a screw pump. The driving motoris a two-pole motor, and the rotational speed of the driving motor isnot variable. The screw pump includes a rotating screw that is driven bythe driving motor. The rotating screw has a lower end immersed in themelted material, and an upper end in contact with air so as to transportthe melted material upwardly to a fluid guide seat. However, since theupper end of the rotating screw is in contact with air, solidified metalresidual may be formed on the rotating screw after long-term use of theconventional pump device. Moreover, since the two-pole driving motor hasa relatively small torque, and since the rotational speed of the drivingmotor is not variable, the conventional pump device is not suitable fordifferent melted materials that have different specific weights.

SUMMARY

Therefore, an object of the disclosure is to provide a pump device thatcan alleviate at least one of the drawbacks of the prior art.

According to the disclosure, the pump device includes a drive unit, apump unit and a transport unit. The drive unit includes a base frame,and a variable-speed drive device that is disposed on the base frame.The pump unit includes a rotating shaft that is driven by an outputshaft of the drive device and that extends downwardly from the drivedevice, a fan blade that is co-rotatably mounted to a bottom portion ofthe rotating shaft, a drain housing that receives the fan blade thereinand that has a drain opening and an inlet opening, and a suction housingthat defines a suction space in fluid communication with the inletopening of the drain housing, and a plurality of suction holes in fluidcommunication with the suction space. The transport unit includes aplurality of transport tubes that are connected in series and that arein fluid communication with the drain opening of the drain housing. Whenthe drain housing and the suction housing of the pump unit are immersedin a melted material, the drive device is operable to rotate therotating shaft and the fan blade, so that the melted material in thedrain housing is impelled by the fan blade to flow into the transporttubes via the drain opening, and that the melted material surrounds thesuction housing flows into the drain housing via the suction holes, thesuction space and the inlet opening.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the disclosure will become apparent inthe following detailed description of the embodiment with reference tothe accompanying drawings, of which:

FIG. 1 is an exploded perspective view illustrating an embodiment of thepump device according to the disclosure;

FIG. 2 is a fragmentary exploded perspective view illustrating a pumpunit of the embodiment; and

FIG. 3 is an exploded perspective view illustrating a transport unit ofthe embodiment.

DETAILED DESCRIPTION

Referring to FIGS. 1 to 3, the embodiment of the pump device accordingto the disclosure is cooperatively used with a casting machine 1. Thepump device includes a drive unit 2, a pump unit 3 and a transport unit4.

The drive unit 2 includes a base frame 21, a drive device 22 that isdisposed on the base frame 21, and a connecting frame 23 that fixedlyinterconnects the base frame 21 and the casing machine 1. In oneembodiment, the drive device 22 is configured as a six-polevariable-speed motor, and has a rated power of 2 horsepowers and amaximum rotational speed of 1500 rpm.

The base frame 21 includes a plurality of support rods 211, aheat-insulation plate 212 that is fixedly mounted to top ends of thesupport rods 211, and a carrier plate 213 that is fixedly mounted to atop surface of the heat-insulation plate 212 and that permits the drivedevice 22 to be fixedly mounted thereon. In one embodiment, each of thesupport rods 211 is configured as a stainless steel rod. Theheat-insulation plate 212 is configured as a Bakelite plate thatprotects the drive device 22 from high-temperature.

The connecting frame 23 is fixedly mounted to the carrier plate 213, andsurrounds the drive device 22 for fixedly interconnecting the base frame21, the drive device 22 and the casting machine 1.

With particular reference to FIG. 2, the pump unit 3 includes a rotatingshaft 31 that is driven by an output shaft of the drive device 22 andthat extends downwardly through the carrier plate 213 and theheat-insulation plate 212, a fan blade 32 that is co-rotatably mountedto a bottom portion of the rotating shaft 31, a drain housing 33 thatreceives the fan blade 32 therein, and a suction housing 34 that isfixedly mounted to a bottom end of the drain housing 33. The drainhousing 33 and the suction housing 34 are immersed in a melted materialduring operation of the pump device.

The drain housing 33 includes an upper housing part 331 that permits therotating shaft 31 to extend therethrough and that defines a drainopening 330 opening in a horizontal direction, and a lower housing part333 that defines an inlet opening 332 opening in a vertical direction.The upper and lower housing parts 331, 333 are interconnected andcooperatively define a drain space 334 that receives the fan blade 32therein and that is in fluid communication with the drain opening 330and the inlet opening 332.

The suction housing 34 is tubular-shaped, is fixedly mounted to a bottomsurface of the lower housing part 333, and defines a suction space 342therein. A top portion of the suction housing 34 is formed with acommunication hole 341 that fluidly communicates the suction space 342with the inlet opening 332 and the drain space 334. A bottom portion ofthe suction housing 34 is closed. A tubular side wall portion of thesuction housing 34 is formed with a plurality of suction holes 343 thatare in fluid communication with the suction space 342. It should benoted that the sum of the areas of the suction holes 343 is equal to orgreater than the area of the drain opening 330, and is no more than 10percent greater than the area of the drain opening 330.

The transport unit 4 includes a bracket 41 that is connected to the baseframe 21, a plurality of transport tubes 42 that are connected in seriesand that are in fluid communication with the drain opening 330 of thedrain housing 33, a plurality of heat-insulation sleeves 43 (only a partof the heat-insulation sleeves 43 are shown in the figures) that arerespectively sleeved on the transport tubes 42, a plurality ofelectroplated layers 44 each of which is formed on an inner surface of arespective one of the transport tubes 42, a plurality of heat-insulationcotton layers 45 each of which is disposed between a respective one ofthe transport tubes 42 and a corresponding one of the heat-insulationsleeves 43, and a handle 46 that is fixedly mounted on a distal one ofthe transport tubes 42 distal from the drain opening 330.

In one embodiment, each of the heat-insulation sleeves 43 includes twointerconnected sleeve halves. In one embodiment, any two adjacent onesof the transport tubes 42 are interconnected by a flexible joint (notshown), so an assembly of the transport tubes 42 is flexible. A proximalone of the transport tubes 42 that is proximal to the drain opening 330is directly connected to the drain housing 33, and is in fluidcommunication with the drain opening 330. The bracket 41 is fixedlyconnected to the proximal one of the transport tubes 42 so that a majorportion of the transport unit 4 is located above the surface of themelted material. Each of the heat-insulation sleeves 43 is made ofstainless steel. Each of the electroplated layers 44 is made of Teflonor a mixture of nickel and phosphorus that is highly hydrophobic, so asto prevent the melted material from adhering to the inner surfaces ofthe transport tubes 42.

When the drain housing 33 and the suction housing 34 are immersed in themelted material for operation of the pump device, the melted materialflows into the drain space 334 via the suction holes 343, the suctionspace 342, the communication hole 341 and the inlet opening 332. Inoperation, the drive device 22 rotates the rotating shaft 31 about anupright axis so as to rotate the fan blade 32 within the drain space334, so the melted material in the drain space 334 is impelled by thefan blade 32 to flow into the transport tubes 42 via the drain opening330. It should be noted that since the sum of the areas of the suctionholes 343 is no less than the area of the drain opening 330, the meltedmaterial that surrounds the suction housing 34 is permitted to smoothlyand continuously flow into the drain space 334 when the melted materialin the drain space 334 is impelled into the transport tubes 42.Moreover, since the drive device 22 (i.e., a six-pole motor) has arelatively low rotational speed and a relatively high torque, the meltedmaterial can be impelled steadily. The handle 46 is configured for auser to hold for moving the transport tubes 42, and has a recess 461(see FIG. 3) that is engaged with the distal one of the transport tubes42. Since the drive device 22 is configured as a variable-speed motor,the pump device of this disclosure is suitable for different meltedmaterials having different specific weights, such as copper alloy, zincalloy and copper-zinc alloy.

It should be noted that the flow rate of a melted material created bythe fan blade 32 is sufficient to fill the drain opening 330 during theoperation of the pump device, so air can be prevented from entering thetransport tubes 42.

In the description above, for the purposes of explanation, numerousspecific details have been set forth in order to provide a thoroughunderstanding of the embodiment. It will be apparent, however, to oneskilled in the art, that one or more other embodiments may practicedwithout some of these specific details. It should also be appreciatedthat reference throughout this specification to “one embodiment,” “anembodiment,” an embodiment with an indication of an ordinal number andso forth means that a particular feature, structure, or characteristicmay be included in the practice of the disclosure. It should be furtherappreciated that in the description, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure and aiding in theunderstanding of various inventive aspects.

While the disclosure has been described in connection with what isconsidered the exemplary embodiment, it is understood that thisdisclosure is not limited to the disclosed embodiment but is intended tocover various arrangements included within the spirit and scope of thebroadest interpretation so as to encompass all such modifications andequivalent arrangements.

What is claimed is:
 1. A pump device comprising: a drive unit includinga base frame, and a variable-speed drive device that is disposed on saidbase frame; a pump unit including a rotating shaft that is driven by anoutput shaft of said drive device and that extends downwardly from saiddrive device, a fan blade that is co-rotatably mounted to a bottomportion of said rotating shaft, a drain housing that receives said fanblade therein and that has a drain opening and an inlet opening, and asuction housing that defines a suction space in fluid communication withsaid inlet opening of said drain housing, and a plurality of suctionholes in fluid communication with said suction space; and a transportunit including a plurality of transport tubes that are connected inseries and that are in fluid communication with said drain opening ofsaid drain housing; wherein, when said drain housing and said suctionhousing of said pump unit are immersed in a melted material, said drivedevice is operable to rotate said rotating shaft and said fan blade, sothat the melted material in said drain housing is impelled by said fanblade to flow into said transport tubes via said drain opening, and thatthe melted material surrounds said suction housing flows into said drainhousing via said suction holes, said suction space and said inletopening.
 2. The pump device as claimed in claim 1, wherein the sum ofthe areas of said suction holes is equal to or greater than the area ofsaid drain opening.
 3. The pump device as claimed in claim 2, whereinthe sum of the areas of said suction holes is no more than 10 percentgreater than the area of said drain opening.
 4. The pump device asclaimed in claim 1, wherein said drive device is configured as asix-pole motor.
 5. The pump device as claimed in claim 1, wherein saiddrive device has a rated power of 2 horsepower and a maximum rotationalspeed of 1500 rpm.
 6. The pump device as claimed in claim 1, whereinsaid transport unit further includes a plurality of electroplated layerseach of which is formed on an inner surface of a respective one of saidtransport tubes, and is made of one of Teflon and a mixture of nickeland phosphorus.
 7. The pump device as claimed in claim 1, wherein saidtransport unit further includes a plurality of heat-insulation sleevesthat are respectively sleeved on said transport tubes.
 8. The pumpdevice as claimed in claim 7, wherein said transport unit furtherincludes a plurality of heat-insulation cotton layers each of which isdisposed between a respective one of said transport tubes and acorresponding one of said heat-insulation sleeves.
 9. The pump device asclaimed in claim 8, wherein said transport unit further includes ahandle that is fixedly mounted on a distal one of said transport tubesdistal from said drain opening.
 10. The pump device as claimed in claim1, wherein said base frame of said drive unit includes a plurality ofsupport rods, a heat-insulation plate that is fixedly mounted to topends of said support rods, and a carrier plate that is fixedly mountedto a top surface of said heat-insulation plate and that permits saiddrive device to be fixedly mounted thereon, said rotating shaftextending downwardly through said carrier plate and said heat-insulationplate.
 11. The pump device as claimed in claim 10, wherein said driveunit further includes a connecting frame that is fixedly mounted to saidcarrier plate, said connecting frame being adapted to be connected to acasting machine.